The sheaths are going to be harder to find as they were separate contract pieces. The best place to find one would be a (military) base auction. When I was stationed at different AF bases they would have auctions periodically. You could get anything from clothing, parachutes to all kinds of parts and different surplus. Of course you have to be near a base to get the listings when the auctions are coming up. And also when you go to these, its a "roll of the dice" as far as what is being auctioned. usually though, they have a day when people can "thumb through" whats going to be auctioned. These liferaft knives and other similar things, are strictly military sales, so when you find things like this, they will be rare (when it comes to the public). The liferaft knive costs (the military) pennies, but they are rare to the public, so it makes them worth a llittle more.